New life given to sewer line

Sewer line work currently underway in northern Cambridge will reduce the amount of seepage into sewer lines through broken or cracked pipes, resulting, ultimately, in cost savings to the city.

Workers from Environmental Pipeliners, Westerville, began work recently to prepare existing pipe and install a liner, designed to restore the integrity of the sewer lines by creating, in essence, a pipe within a pipe, said City Engineer Paul Sherry.

In all, about 5,000 feet of sewer line will be treated. Of this, 1,600 feet is 8-inch line, and 1,500 feet is 18-inch line. The remainder falls in between in diameter.

Workers will use pressurized air to force the liner, heavy resin-impregnated felt, inside out through each portion of the targeted sewer line. When pulled back through, the liner will be in its proper position. Steam will then expand the liner and activate the resin, and it will cure and harden, creating a smooth and durable surface within the piping.

The largest stretch of piping to be affected is along Gordons Run between North Fourth and North Sixth streets. Work will also be performed along portions of Steubenville Avenue, and along Blaine Avenue between North 10th and North 11th streets. As well, some lateral lines will be treated.

Though some road closings are expected, Sherry said, they should be minimal as once the crews begin working, they continue until the target portion of sewer line is completed.

The approximately $500,000 project is funded through a low-interest water pollution control fund loan through the state, to be repaid over the next decade, Sherry said. Annual payments are expected to be about $110,000 per year, less than originally expected as bids came in lower than estimates.

Cracked and broken sewer piping allows for ground seepage to enter the system, increasing the volume of water making its way to the water pollution control plant to be treated. Decreasing the volume of fluid treated saves money, as less treatment materials are used in the process, and the equipment is operated at lower capacity.